Vray RT GPU % Use question.

[ripe]

I have finally managed to squeeze 3 GPU's into my main machine - a 1070 and 2x 780TI.

My question is when using 'Activeshade' whilst working - the statistics bounce around all over the place from 60% ish to the high 90% for GPU usage - is this normal?
I would have thought as one is interacting with the scene and altering things the usage should be maxed out most of the time?

using Vray 3.5 (not put the latest / recent patch / upgrade on yet)

I've tried it with just one GPU selected and get the same fluctuating results?

[ripe]

Done a few tests - if I use the 2 GPU's (1 x 1070 and 1x780ti) that are not used for the display I get around 95% GPU usage when using Activeshade and manipulating the scene.
When I use all 3 GPU's - which includes the other 780ti that is used for the screen - I get around 75% GPU usage across all 3 GPU's - weird? Any ideas why it drops so much when using all 3?

[ripe]

Updated to 3.504 - latest and no change.
Bringing that extra GPU (my display one) seems to knock the performance.

Anyone else experiencing this?

[piotrus3333]

it's normal.
just exclude one 780 from rendering.

[allemyr]

I'am having the same sort of questions. Did some tests before weekend and I also get these low range of percentage usage when using both my Titan X and a 780ti in active shade. Why I have start investigating in this is because I only have two slots for graphicscard and planning to use a 1080ti with my Titan X. And render with both of them. My dream is that the first card is used to 95% and the other 100%. That would be great to get faster feedback in active shade!

[savage309]

The utilization settings in active shade by default are lower - jobs are given to the GPU in smaller chunks, so they can be computed faster and the feedback could be better. When using V-Ray GPU as production, the settings are optimized for high utilization (you can check ray bundle size and rays per pixel settings here https://docs.chaosgroup.com/display/...X/V-Ray+RT+FAQ). The ray bundle size / rays per pixel can be manually tuned as well - they are in the advanced RT settings.
Worth mentioning is to check if you have "low gpu thread priority" on. If you have it this might decrease the utilization as well.

Best,
Blago.